Burglar alarm



Dec.l2l, 1948. B. w. SMITH BURGLR ALARM Filed oct. 25. 194e BERN/IRD WM/ 7W.v BY

/77' TURA/EY.

Patented Dec. 21, 1948 iU N1 TED as Pars-N o Frio E. f

"rst-IRGLAR ALARM* Bernard Smith, Hartford, Conn.

Application l Oc,to"neri,?.5, 1946, 'Serial N o. 705,746 5 Claims. (Cl. .luie-'90) This 4'invention relates to vburglar alarms ffor windows and more vparticularly to devices -fsuc'h asare 4intendedto operate an alarm upon unauthorized attempts to either open or close a window.

An object of vthis invention vis to provide such an alarm which'is `particularly adapted for use iin'w'indows :of buildings land which fmay be operated through the movement o'ffthe A.wind-ovv sash.

A furtherobject-offthe invention fis 1to provide a burglar alarm which may be fitted in a conven- 4tional(window frame in place'of the ordinary sash pulley, so as lto Asupport the window `sash by 'means 'of the vconventional cord thereof., land which is 'operated -by said cord Ifor rendering yan alarm.

Further objects and advantages of this invention will be more clearly understood from the following description and from the accompanying drawings, in which- Fig. 1 is a sectional side view of my improved burglar alarm, on line I-I of Fig. 2, and showing a portion of the window frame and sash.

Fig. 2 is an elevational front View of said alarm with the front plate thereof removed.

As shown in the drawings, the numeral 5 denotes a porti-on of a conventional window frame in which there is ordinarily employed a sash 6 Which moves in said frame for opening and closing the Window.

In the embodiment of my invention shown, the alarm mechanism consists of a casing 'I having anges 8 by means of Which the said casing is positioned Within an opening in the side of the window frame and secured therein by means of screws 9 which also secure in position a cover plate It.

A pulley II is mounted upon a shaft I2 which is pivoted to said casing and rotates with the pulley. A gear I3 is also secured to said shaft and driven thereby to rotate a pinion I4 on the shaft I5 which carries an escapement or cam wheel I6. An actuating rocker lever I'I is secured to a shaft I8 which is also pivoted in the case and carries a hammer I0 and pull lever 20 that is actuated by a pull rod 2 I. A bell 22 is secured Within the case I in position to be struck by the hammer I9.

As illustrated in Fig. 1, the sash 6 is hung by means of the cord 23 which is mounted over the pulley II and has a counterweight 24 secured to the end thereof for counterbalancing the sash 6.

In the operation of my improved burglar alarm, any movement of the window sash 6 by an unauthorized person to either raise or lower it Will, through the cord 23, rotate the pulley II which in lturn will rotate the shaft 1I2,rthe=gear t3 and the" pinion im, and vthereby cause rotation 'of `the Icamwfheel It to actuatetheilever `Eil against'the action vofthe spring lil-a and vibrate the-hammer I9 lagainst the bell "22 to lrender fan audible lalarm signal.

W hen lit `is ldesired ftomake the mechanism lof Hout of engagement with-thecam wheel I6, so

'that rotation yof Asaid "Wheel, during normal rais-- ingl orllowering ofthe window sash, will not cause ringing 'ofthe bell 22. v

It will be noted that my improved burglar alarm device, when conditioned to be operative, will op.. erate immediately upon an attempt being made to move the sash 6 from a iiXed position, and that movement of the sash in either direction will immediately cause the said device to render an alarm. Therefore, no setting of the device, or of the window sash, is required in order to make the said device operative other than to merely release the cord 2 I.

I claim:

-1. A burglar alarm for a window having a frame, a sash slidable in said frame, a cord run-- ning along the side of said frame and having an end secured to said sash; the said alarm comprising a casing secured to the side of and within said frame, a pulley rotatable in said casing and adapted to receive said cord, Weighted means within the frame providing frictional engagement between said cord and pulley for rotation of said pulley upon movement of the sash, a cam wheel rotatable by said pulley, a bell, and a hammer operable upon rotation of said cam wheel for striking said bell to render an audible signal.

2. A burglar alarm for a window having a frame, a sash slidable in said frame, a cord having one end thereof secured to said sash and its other end secured to counterbalancing means for suspending said sash; the said alarm comprising a casing having a cover plate secured to the side of and within said frame, a pulley rotatably mounted in said casing adjacent to said plate and projecting slightly therethrough for receiving said cord for rotation of the pulley upon movement of the sash, a cam wheel rotatable by said pulley, a bell adjacent the surface of said side, and a hammer operable upon rotation of the cam Wheel for striking said bell to render an audible signal:

3. A burglar alarm for a window having a frame and a sash slidable in said frame, a cord having one end thereof secured to said sash, counterbalancing means secured to the other end of said cord; the said alarm comprising a casing mounted in an opening in one side of and within the said frame, the said casing being open at said side and having a detachable cover plate at said side of the frame for closing said casing, a pulley rotatable in said casing and extending slightly through an opening in said cover plate for receiving said cord for rotation of the pulley upon movement of the sash, a cam wheel rotatable by said pulley, a bell within said casing and posif tioned adjacent to said plate opposite openings therein, and a hammer operable upon rotation of said cam wheel for striking said bell to render an audible signal.

4. A burglar alarm for a window having a frame, a sash slidable in said frame, a cord for suspending said sash; the said alarm comprising a casing having inner, upper and lower walls and mounted within an opening in the side of said frame, ears extending from said casing, mechanism contained within said casing and including a bell, a striker, cam means, and a pulley rotatably mounted within said casing and projecting slightly from the side of said frame and adapted to rotate said cam means for operating said striker to strike said bell, a cover plate for closing said casing extending over said ears, means securing said cam plate and ears to the side of the frame for securing the casing to the frame and closing said casing, the said cover plate having a slot therein to permit said pulley to project therethrough into the said frame; a cord secured to the sash and running along the side of the frame, over said pulley and downwardly therefromr between the said inner wall of the casing and the cover plate and through the bottom wall of the casing at the opposite side of the said side of the frame, a weight secured to the lower end of the cord for counterbalancing said sash, a lever connected to the striker and projecting through the inner wall of the casing for rendering said striker inoperative by said cam means, and a pull cord for operating said lever.

5. For a, burglar alarm of the character described, a window construction comprising a frame, a sash, a pulley within said frame, means operable upon rotation of said pulley for rendering an audible signal, a flexible member connected to said sash and extending over said pulley for causing rotation of the pulley upon movement of said sash, and sash counterbalancing weighted means within said frame connected to said flexible member for retaining it in driving engagement with the pulley.

BERNARD W. SMITH.

REFERENCES CITED The following references are of record in the file of this patent: v

1 UNITED STATES PATENTS Number 

